package com.ruoyi.message.util;

import org.springframework.stereotype.Component;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

@Component
@ServerEndpoint("/websocket/{userId}")
public class WebSocketUtil {

    // concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
    private static CopyOnWriteArraySet<WebSocketUtil> webSocketSet = new CopyOnWriteArraySet<>();

    // 与某个客户端的连接会话，需要通过它来给客户端发送数据
    private Session session;

    // 用户ID
    private String userId;

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") String userId) {
        this.session = session;
        this.userId = userId;
        webSocketSet.add(this);
        System.out.println("有新连接加入！当前在线人数为：" + webSocketSet.size());
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        webSocketSet.remove(this);
        System.out.println("有一连接关闭！当前在线人数为：" + webSocketSet.size());
    }

    /**
     * 收到客户端消息后调用的方法
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        System.out.println("来自客户端的消息:" + message);
    }

    /**
     * 发生错误时调用
     */
    @OnError
    public void onError(Session session, Throwable error) {
        System.out.println("发生错误");
        error.printStackTrace();
    }

    /**
     * 群发自定义消息
     */
    public static void sendInfo(String message) throws IOException {
        for (WebSocketUtil item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                continue;
            }
        }
    }

    /**
     * 发送消息
     */
    private void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }
}
